#!/bin/dash
### BEGIN INIT INFO
# Provides:          Node exporter
# Required-Start:    $local_fs $network $named $time $syslog
# Required-Stop:     $local_fs $network $named $time $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Description:       Node exporter for prometheus written in Go
### END INIT INFO

DAEMON=/usr/local/bin/node_exporter
NAME=node_exporter
USER=devops
PIDFILE=/var/run/prometheus/$NAME.pid
LOGFILE=/var/log/prometheus/$NAME.log
LISTEN=`hostname -I|awk '{print $1}'`:9100

ARGS="--web.listen-address=$LISTEN"


[ -r /etc/default/$NAME ] && . /etc/default/$NAME

do_start_prepare()
{
    mkdir -p `dirname $PIDFILE` || true
    mkdir -p `dirname $LOGFILE` || true
    chown -R $USER: `dirname $LOGFILE`
    chown -R $USER: `dirname $PIDFILE`
}

do_start_cmd()
{
    do_start_prepare
    echo -n "Starting daemon: "$NAME
	start-stop-daemon --chuid $USER -C --background --start --quiet --pidfile $PIDFILE --make-pidfile --exec $DAEMON -- $ARGS >> $LOGFILE 2>&1
    if [ $? -eq 0 ];then
        echo  "\033[32m [ OK ] \033[0m"
    else
        echo  "\033[31m [ FAILED ] \033[0m"
    fi

}

do_stop_cmd()
{
    echo -n "Stopping daemon: "$NAME
	start-stop-daemon --stop --quiet --oknodo --pidfile $PIDFILE && rm -f $PIDFILE
    if [ $? -eq 0 ];then
        echo  "\033[32m [ OK ] \033[0m"
    else
        echo  "\033[31m [ FAILED ] \033[0m"
    fi

}

uninstall() {
  echo -n "Are you really sure you want to uninstall this service? That cannot be undone. [yes|No] "
  local SURE
  read SURE
  if [ "$SURE" = "yes" ]; then
    stop
    rm -f "$PIDFILE"
    echo "Notice: log file was not removed: '$LOGFILE'" >&2
    update-rc.d -f <NAME> remove
    rm -fv "$0"
  fi
}

status() {
    echo -n "Checking $NAME:				"
    if [ -f $PIDFILE ]; then
        PID=$(cat $PIDFILE)
            if [ -z "$(ps axf | grep ${PID} | grep -v grep)" ]; then
                echo  "\033[31m [ The process died, but the PIDFILE was still there. ] \033[0m"
            else
                echo  "\033[32m Running, the PID is $PID \033[0m"
            fi
    else
        echo  "\033[31m [ Service not running ] \033[0m"
    fi
}


case "$1" in
  start)
    do_start_cmd
    ;;
  stop)
    do_stop_cmd
    ;;
  status)
    status
    ;;
  uninstall)
    uninstall
    ;;
  restart)
    do_stop_cmd
    do_start_cmd
    ;;
  *)
    echo "Usage: $1 {start|stop|status|restart|uninstall}"
    exit 1
esac

exit
